There's a foul smell in the kitchen.

He called the ball foul.

They should never play foul.

The water was fouled by oil.

The ship's hull was covered in fouling.

The batter hit a foul ball.

The ball landed just outside the foul line.

There was evidence of foul play in the game.

His foul-up caused a lot of confusion.

She wore a beautiful foulard around her neck.